Wire-tie forming and twisting tool

ABSTRACT

A tool for applying, forming, and twisting a wire-tie at rod cross-over points of concrete reinforcement grids and the like, having releasable jaw clamping means to grip intersecting rods together at right angles, wire feeding means to direct the legs of a pre-formed hair-pin like looped wire onto anvil surfaces in said clamping jaws and engage the looped end thereof against one of the rods while said legs are being reversely turned around the other rod with the free ends thereof straddling said first rod, and means for twisting said free ends together. The wire-tie so fastened is characterized by opposed pairs of spaced loops embracing the rods, the loops of the pair about each rod lying in a parallel planar relation to each other and in perpendicular planar relation to the plane of each loop about the other rod. The tool, by sequentially operating actuator means, clamps the jaws, feeds and forms the legs of the preformed wire, twists the free ends, and then releases the jaws in a single reciprocating stroke.

lJnited States Patent [1 1 Albrecht et a1.

[ Jan. 22, 1974 1 WIRE-THE FORMING AND TWlSTING TOOL [75] Inventors: Clifford C. Albrecht, Leicester;

' Howard G. Brown, Worcester, both of Mass.

[73] Assignee: Novelty Tool Company, Inc.,

Spencer, Mass.

[22] Filed: Oct. 13, 1972 [21] Appl. No.: 297,360

[52] US. Cl. 140/119, 140/93 A Primary Exarhiner- Lowell A. Larson Attorney, Agent, or Firm Chapin, Neal and Dempsey [57] ABSTRACT A tool for applying, forming, and twisting a wire-tie at rod cross-over points of concrete reinforcement grids and the like, having releasable jaw clamping means to grip intersecting rods together at right angles, wire feeding means to direct the legs of a pre-formed hairpin like looped wire onto anvil surfaces in said clamping jaws and engage the looped end thereof against one of the rods while said legs are being reversely turned around the other rod with the free ends thereof straddling said first rod, and means for twisting said free ends together. The wire-tie so fastened is characterized by opposed pairs of spaced loops embracing the rods, the loops of the pair about each rod lying in a parallel planar relation to each other and in perpendicular planar relation to the plane of each loop about the other rod. The tool, by sequentially operating actuator means, clamps the jaws, feeds and forms the legs of the preformed wire, twists the free ends, and then releases the jaws in a single reciprocating stroke.

8 Claims, 10 Drawing Figures PAIENIE JAN221974 sum 1 BF 3 1 WIRE-TIE FORMING AND TWISTING TOOL BACKGROUND This invention relates to apparatus for fastening 5' particular to provide a tool .for clamping the rods together, then feeding and forming preformed, U-shaped, hair-pin like wire loop into place around said rods and finally twisting the wire ends so as to produce a double-sling type of tie having opposed pairs of spaced loops securing said rods at right angles. In a completed tie, one pair of spaced loops lies in a generally parallel planar relation embracing one of the rods while the legs thereof which connect said loops are reversely turned to provide an opposed pair of loops about the other rod. The opposed pair of loops also lie in spaced parallel planes perpendicularly disposed to the parallel planes of the other pair. The double-sling method of fastening a tie not only holds the intersecting rods securely together, but also effectively resists forces tending to cause the rods to shift from the right angular relatron.

Wire-tying or wire-twisting tools for automatically fastening the intersecting rods of reinforcement grids in concrete constructional work are known in the art as exemplified by U.S. Pat. No. 3,169,559 of Feb. 16, 1965. In the latter patent apparatus is disclosed for engaging the crossed rods of a grid by directing the legs of a hair pin like wire tie around the rods at diagonally opposed corners of the intersection thereof. Thus the pre-formed loop of the tie embraces one rod and the twisted free ends of the legs thereof forma second opposed loop in the same plane to embrace the other rod. All prior tools, insofar as is known, produce this type of finished wire tie. A single loop or sling around each rod with the legs extending there-between at diagonally opposite corners of the intersection will permit a shifting of the crossed rods into a diagonal relationship. Where, as happens frequently, a grid is being set up vertically it is thus subject to, at least, partial collapse after the manner of a lazy tongs action. The present invention forming a double-sling wire tie, as above outlined, effectively resists any such tendency of a grid to collapse in this fashion.

Further, prior wire-twister tools, insofar as is known, also lack an effective clamping means to hold the crossed rods securely together during the application and forming of the finished tie. Thus the degree to which the rods are forced together in an accurate right angled relation is to a certain extent dependent on the skill or attention of an operator in manipulating the tool. The present apparatus is designed to eliminate the chance for human error or carelessness by provision for sequential operation which begins with a jaw clamping operation followed by a feeding and forming operation on the tie and twisting the ends, a jaw opening action taking place only after the final loop is twisted. Thus,

- the tool by clamping the rods together during forming and twisting operations insures a tight binding of the rods at the cross over point.

SUMMARY OF THE INVENTION The present invention contemplates apparatus in which sequentially operated mechanism is provided to:

first hold the crossed rods releasably clamped by bifurcated jaw members in accurately positioned relation, as in a portable vise-like fixture; next to feed the legs of a U-shaped wire on opposite sides of one rod into grooved anvil surfaces of the clamping jaw members and form semi-circular loops snugly embracing the other cross rod with the legs being directed back in straddling relation at opposite sides of the first rod; ad finally, when the bight of said U-shaped wire embraces the first rod twisting the free ends of said legs into an end loop in spaced relation to said bight and opening said jaws to release said rods.

An embodiment of the invention is disclosed herein as a hand operated tool having a push-pull handle. Bifurcated lower curved jaw members mounted at the end of elongated frame rails straddle one of the crossed rods and hook onto the other rod. A pair of handle rails have a fixed drive connection with a stripper blade which is slidably supported between said frame rails. On commencing an inward handle stroke the blade advances a U-shaped wire from a magazine supply while upper bifurcated jaw members at the fore-end of an overhead twister block of a novel design are pushed into clamped condition agalnst the lower jaws. A forward clutch drive connection between the twister block and handle rails is engaged forthis latter movement and when the jaws are clamped the clutch is disengaged. The wire is then further advanced by the blade to feed the free ends thereof onto anvil surfaces in the spaced jaw members and be formed around the rods and reversely directed to push wire end portions into the twister block. The handle is then retracted and during a reverse stroke the wire ends are automatically twisted in place, the clamping jaws being then opened for release of the wire ends from the twister block and removal of the tool from the rods.

While a hand operated tool is primarily disclosed herein the actuating parts are readily adaptable for power operation.

The above and other objects and advantages of the invention will be apparent from the following disclosure of a preferred embodiment thereof.

FIGURES FIG. 1 is a side elevation of a hand tool embodying the invention with parts broken away and in section, illustrating the position of the parts midway in the operation of the tool and prior to anchoring a tie wire in place by operation of the twister assembly;

FIG. 2 is a perspective view showing a completed wire tie fastened on a pair of intersecting rods;

FIG. 3 is a side elevational view of the fore-end of the tool of FIG. I with parts in section showing the twister assembly and movable jaws in open position;

FIG. 4 is a transverse sectional view on line 4-4 of FIG. 3;

FIG. 5 is a transverse sectional view on line 5-5 of FIG. 3;

leg members for closing action of the upper jaw assembly; and

FIGS. 9 and 10 are fragmentary views to illustrate stages in the operation of the drive connection shown by FIG. 8.

DESCRIPTION OF AN EMBODIMENT OF THE INVENTION The wire tie produced by a tool of the present invention is formed as above mentioned from a U-shaped or elliptical hairpin-like wire w as seen in FIG. 7, this looped pre-form being stripped from the top of a magazine supply by a stapler like driver-blade. The looped wire is shaped and fastened by tool operation at a rod cross-over point of a grid, the free ends being twisted together as in the finished tie shown by FIG. 2. As there shown, the loop 1 of the preform embraces one of the rods in spaced relation to the loop at 3, which likewise embraces the same rod and is formed by twisting the free ends together. Loops 1 and 3 lie in parallel planes. The legs connecting these loops are reversely bent as the pair of loops at 5 and 7 embracing the other rod. Loops 5 and 7 also lie in spaced parallel planes perpendicular to the planes of loops 1 and 3. As will readily be appreciated this form of wire-tie with a double sling" around each rod resists any tendency of the rods to shift angularly relative to one another and thus more securely maintains the desired right angular relationship. This is in contrast to the more conventional wiretie form having a single loop embracing each rod diagonally across opposite corners at the intersection thereof.

MAIN FRAMEWORK The main frame elements on which the various operating parts of the tool are mounted include a pair of spaced side rail members 2 and 4 (see FIGS. 4, 6, 8). At the front end of each of the rails 2 and 4 are fixed lower hooked jaw portions 6 and 8 (FIG. 7) having grooved anvil wire-forming tracks 10, the jaw portions being spaced to straddle one of a pair of crossed rods ofa grid, as the vertical rod 12 in FIGS. 1 and 2 and be hooked onto the other cross rod 14 perpendicular to rod 12. When the rods are clamped together by the lower jaws 6 and 8 and by upper jaw portions as will be described, the grooved anvil tracks serve to guide the spaced free ends of a looped wire w as will also be later described in detail.

The rails 2 and 4 are maintained in parallel relation by various frame spacer elements. At the rear end a depending spacer portion 16 of a bearing block 18 (FIG. 1) fits between the rails, the block 18 rotatably holding the rear end of a spinner shaft 70 above the rails. Spacer portion 16 is fixed between rails 2 and 4 as by a rivet connection indicated at 22.

Centrally of rails 2 and 4 another spacer block is located as at 24 (FIG. 1) holding the rails connected in parallel relation as by a rivet indicated at 28. Block 24 is suitably seated on the top of a tool handle member as the pipe 26.

At the front end a spacer block 30 holds the front jaw portion of the rails accurately positioned, the block being ahchored therebetween as by a tie bolt 32 which also secures at its outer ends a pair of cover plates 34 and 36 (see also FIGS. 4 and 6).

The three spacer elements as described hold the guide rails rigidly secured together. As may be noted from FIGS. 1, 3, 4, and 7, the inner top edges of the rails are cut as at 38 and 40 to provide opposed tracking means for slidably mounting a wire stripping and driver blade 42 which engages the closed end of a topmost wire loop fed upwardly between the rails from a stacked spring-urged magazine supply. The blade thus feeds the free ends of the loop into the entrance of the anvil grooves 10 which are upwardly curved in the front lower jaw portions (see FIG. 7). It may also be noted from FIG. 7 that in the section where the wire loops are fed upwardly the blade tracking edges 38, 40 are outwardly flared. This permits the ready entrance of the looped wire legs between the rails in order for the closed end to be readily picked up by the forward edge of the blade 42.

The framework as above described in outline provides the fixed supporting structure upon which the movable elements of the tool are mounted for operation therewith.

UPPER JAW BLOCK AND CLAMPING PUSI'IER Referring now particularly to FIGS. 1 and 3 an upper jaw clamping block generally indicated by numeral 50 and an actuating clamp pusher therefor generally indicated by numeral 52 are shown. As shown the pusher 52 straddles the fixed frame rails 2 and 4 and is mounted for a limited longitudinal movement along the v rails sufficient for opening and closing action of the spaced upperjaw members at 54 and 56. In closed position the upper jaws abut the lower jaws (FIG. 1) and limit forward movement thereof. In retracted position the upper jaws are retracted as in FIG. 3 and the rear end edge of the pusher 52 which is formed with a rear saddle portion at 58 (see FIGS. 1 or 6) will abut the lower front edge of bearing block 18 and so limit rearward travel. The saddle portion 58 at its front edge has an upstanding pusher tab 60 formed to carry the pusher 52 rearwardly as will later be described.

Referring now to FIG. 8, pusher 52 has leg rails slidably engaged along the outer sides of frame rails 2 and 4. Below the saddle portion 58 ball clutch members 62 lie in opposed openings of the legs. These clutch members provide for the relative movement of a pair of push-pull handle rails and the forward driving engagement of the pusher 52 as will be later described in detail. As best seen in FIGS. 1 and 6, a front web or saddle portion at 64 connects the leg rails at the fore end of the pusher 52. Web 64 is also provided with an upstanding front extension 66 see also FIG. 5) having a center opening at 68 through which the front end of the spinner or twisting shaft 70 extends. In the upper corners of the extension 66 a pair of screw bolts 72 serves to anchor the pusher to the rear of the upper jaw block 50.

Upper jaw block 50 is rectangular in outline as in FIGS. 1 and 3, having a cylindrical bore 74 in which is mounted a spring urged twister assembly generally indicated by numeral 76 (FIG. 1) for winding the free ends of a tie wire together. The fore-end of the block 50 (FIG. 6) is provided with the forked upper jaw members 54 and 56 to straddle the rod 12 and engage the lower jaws. As best seen in FIG. 3, the tips of the upper jaws are provided by separately mounted block extensions 78 providing the jaw nose portions by which the tool jaws are accurately clamped together on the rods 12 and 14.

The nose extensions 78 are attached to the forked ends by screw bolts as at 80, being accurately positioned as by dowel pins as indicated at 82. Anvil grooves as at 84 are provided at each inner edge of the jaws to receive and guide the free ends of the wire legs into the twister assembly as will be later described.

HANDLE AND HANDLE DRIVE As mentioned, travel of the upper jaw clamp block 50 and pusher 52 is limited to an extent sufficient to open and close the jaw portions for application or removal of the tool. This motion is imparted to the pusher member 52 by the handle assembly which includes an outer hand grip 90 (FIG. 6) at the rear end thereof. From handle 90 two spaced drive rails 92 extend along the outside of the pusher legs or rails'(see also FIGS. 1 and 8). As in FIG. 1, the inner ends of the rails 92 are joined by a connecting web shown at 94 straddling the rails 2 and 4 and the legsof the clamp pusher. The web 94 is formed with upwardly directed spaced front and rear mounting plates96 (see FIG. 6) for supporting a spinner nut 98. Nut 98 during forward and rearward travel engages the worm portion 100 of spinner shaft 70 to turn the latter. Web 94 (FIG. 1) also has a central opening in which is received a driving lug or button 102 at the rear of the stripper or wire feeder blade 42. As will be appreciated a full forward handle stroke carries the blade 42 across the top of the magazine indicated at 104 in order to pick up a top-most wire loop and push the same into the jaws and the looped end snugly against the rod 12 (see FIG. 1). It may be noted in this connection that the spacing between the front and rear webs 64 and 50, respectively, of the pusher 52 is sufficient for the required longitudinal travel of the driving button 102 and the handle web 94 when the pusher 52 remains stationary after jaw closing action and during the feeding and forming of the wire loop into the relative position of the parts shown in FIG. 1.

As seen in FIGS. 1 and 6, it will be apparent the parts of the device are positioned at a midpoint of an operating cycle. From such position the handle is pulled outwardly in order to twist the wire endsand then retract the upper jaws for release of the tool from the rods. In retracting the handle from the position shown, the spinner nut 98 first travels rearwardly as to the right in FIGS. 1 and 6. During such travel the spinner nut traverses the worm portion 100 and causes twister assembly 76 to tie the free ends of the wire together into the condition shown by FIG. 2. It will also be seen that the rear upstanding plate 96 at the end of the worm section 100 will thereafter engage the upstanding tab of the pusher block member 52. Upon such engagement the pusher is carried rearwardly by the nut until the rear end edge of saddle 50 abuts the bearing block 18 and stops further retraction. This action, of course, withdraws the upper jaw block rearwardly to the extent desired and into the position seen in FIG. 3.

On forward motion of the handle during a subsequent operating cycle, the handle rails have a driving connection with the pusher 52 so as to advance the pusher forwardly to the jaw block clamping condition as in FIGS. 1 and 6, whereupon the driving connection between the handle rails and pusher 52 is disengaged to allow the handle to continue advancing and complete the wire loop feeding and forming portion of the cycle.

The mechanism for engaging and disengaging the driving connection between the handle rails and legs of pusher member 52 is shown by FIGS. 8, 9, and 10. In FIG. 8 the outer handle rails 92 are shown in the relative position of the parts as in FIG. 6. The recessed dimples 110 shown by dotted line in legs 92 by FIG. 8 have thus been carried into a forward position relative to ball clutch members 62 in the pusher rails. Dimples 110 are close to the forward end of the handle rails, that is, near the front connecting web 94 (see FIG. 6). From this latter position the handle rails will be carried rearwardly until the spinner nut assembly engages the tab 60. At this point of rearward travel the dimples 110 will be oppositely registered with the ball clutch members 62 carried in the pusher rails. Further rearward motion, by engagement of the nut mounting plate 96 and tab 0, retracts the pusher and upper jaws while at the same time the ball members 62 are kicked into the dimples 110 to be free to travel therewith as shown in FIG. 9 and into a rearward offset position relative to a pair of spaced opposed recessed dimples 112 provided in the stationary frame rails 2 and 4.

Forward movement of the handle from this extreme open position will result in a driving engagement between the handle rails and the pusher rails. The balls 62 by maintaining a clutched engagement in the dimples 110 will drive the pusher 52. This clutch drive continues only until such time as the upper jaws abut the lower jaws (as in FIG. 1). At this point the balls 62 as in FIG. 10 are positioned again opposite the dimples 112 of the stationary rails. Accordingly, continued forward thrust of the handle rails 92 as in the direction of the arrow in FIG. 10 will kick the balls out of recesses 110 and over into the dimpled recesses 112 of the frame rails and permit further travel of the handle rails relative to the stationary frame rails and pusher legs.

TWISTER SHAFT AND WIRE END TWISTER As previously noted the twister shaft is square in cross section and has a worm section at to cooperate with the twister nut 98 for twisting the wire ends during rearward travel. The nut 98 is of a standard type of construction having opposed turning members (not shown) for engaging the worm at opposite sides of the .latter and causing the shaft 70 to spin as the nut moves along the worm. The shaft 70 at the rear is suitably journalled for rotation in the bearing block 18. At its front end the shaft passes through an opening of the upstanding front plate 66 of the lcmap pusher and into the rear end section of the cylindrical bore of clamp block 50 (FIG. 3). The shaft here engages a square opening at the rear of a twister assembly rotatably seated in a cylindrical bore of the block 50 as seen in FIG. 3.

The twister assembly is cylindrical and as shown comprises a twister cylinder 120, an internal holder 122, and a pin connection 124 securing the cylinder and holder together. The cylinder has a stepped cylindricaL bore in which the holder 122 is mounted, the shaft 70 being keyed in the rear opening of the holder. Cylinder 120 and holder 122 rearwardly of the pin connection at 124 provide an annular pocket in which a coiled spring 126 is seated against an internal shoulder of cylinder 120, the other end being seated against the upstanding pusher plate 66. The flanged rear end at 128 of cylinder 120 is positioned in an enlarged shouldered section at the rear of the cylindrical bore of the block itself. This permits a limited longitudinal movement of the twister cylinder 120 against the pressure of the spring 126. Forwardly of pin 124 the cylinder has a further stepped shoulder against which the fore-end of holder 122 is seated. Centrally at this forward end is a tapped hole in which an adjusting screw 130 is threaded. The head portion of screw 130 as shown is tapered, and as will be noted from FIGS. 3 and 4, is positioned in the inner end portion of a conically shaped opening 132 formed in the foreportion of cylinder 120.

As shown in FIG. 4 the conical opening 132 is provided with opposed inwardly converging wire tip receiving grooves 134 at three and 9 oclock positions for guiding the free end sections of the looped wire legs into position at each side of the adjusting screw head for wire twisting action. The head of screw 130 holds the wire ends anchored in the grooves during twisting. As the ends are being wound about each other, it will be clear that the tips will retract from an initial extend position to gradually slip outwardly of the adjusting screw head. As may be noted from the fastened wire tie of FIG. 2, the twisting action is for about two and l/4 turns.

It will also be noted in considering the assembly shown in FIG. 3 that movement of the twister cylinder 120 in the block 50, as to the right against spring 126, will take place by the action of the wire ends pushing against the cylinder when inserting the same for passage through the grooves 134. This frictional resistance will at least partially compress spring 126 and thus will float the cylinder in block 50 as indicated in FIG. 1. During twisting action by rotation of the cylinder 120, and the consequent shortening of the wire ends lying in grooves 134, the spring 126 will advance the cylinder in the block and so serve to maintain engagement of the wires in the grooves and under the head of screw 130.

On completion of the twisting in the one direction for approximately two and one-half turns and thus tying the wire ends together, any binding of the wire ends in the grooves, which might otherwise occur, is relieved by a reverse rotary movement for approximately oneeighth turn. This short reverse turning action is imparted to the twister cylinder by an end portion of the worm 100 as at 138 (FIG. 6). Following the short reverse turn of the cylinder, and as previously mentioned, the spinner nut 98 on further retraction of the handle causes the block 50 to retract and thus the twister cylinder is also retracted. Because of the partial reversal of shaft rotation, the tip ends of the twisted wires will not bind in the grooves and are thus efficiently freed to allow an easy removal of the tool from the now fastened cross rods.

It will be apparent from the above description of the apparatus shown in the drawings and cycle of operation actuated by a push-pull handle stroke that a practically fool-proof tool is provided to clamp the rods, apply the tie, and twist in place accurately and tightly with little chance for human error. In contrast to prior tools, as exemplified by the previously mentioned prior U.S. Pat. No. 3,169,559 and having twisting mechanism positioned in opposing relation to a wire feeding means on opposite sides of the crossed rods, all the moving parts of the present invention are located at one and the same side with respect to crossed rods.

This feature enables the clamping members to accurately position the tool for operation without more than casual attention by the operator. Because of the ball clutch drive connection and arrangement the handle rails will not be free to complete the stapler-like driver feed unlessthe clamping jaws are first closed completely on the crossed rods. This, of course, assures the correct positioning of the wire leg portions and the operator need only complete the full push-pull stroke for automatically anchoring the finished tie in place.

It may also be particularly noted that the lower jaw members with hooked end portions 6 and 8 form the extreme end sections of the tool. Accordingly, where a reinforcing grid is being tied together against a closely spaced concrete form surface and a limited clearance is available the hooked end portions of the present tool will enable the crossed rods to be conveniently tied together at a final installation location rather than necessitating grid assembly to one side and then moving it into place. In many instances a reinforcement grid for a thin slab of concrete cannot be tied together in situ" because of the lack of sufficient clearance making manual tying awkward or extra handling necessary if tools are used. The present structure provides a tool for working in restricted spaces to overcome this type of problem.

We claim:

1. Apparatus for fastening and twisting a looped tie wire on crossed rod members comprising a frame having forked parallel end portions provided with arcuate wire forming surfaces and serving as a first anvil means,

means for progressively feeding the legs of a U- shaped wire tie member in an endwise path of travel against said anvil surfaces to impart reverse bends in said legs lying in parallel planes normal to the plane of the looped end of said member,

a second anvil means having forked parallel portions provided with surfaces for progressively receiving the bent leg portions from said first anvil means and rebending said portions to lie in spaced substantially parallel relation to the leg portions adjacent the looped end of said tie member,

means associated with said second anvil means for receiving the tip ends of said legs therefrom and operable to twist said ends together,

said first anvil means and the said second anvil means including said twisting means being relatively movable to close and separate said first and second anvil means to apply said U-shaped tie wire on a pair of right angular intersecting rods and upon separating movement to operate said twisting means.

2. Wire-tie fastening apparatus for binding concrete reinforcing grids and the like at rod cross-over points, said apparatus having releasable clamping means for holding a pair of rods together at right angles,

means to progressively feed a pre-formed hair-pin like wire loop to said clamping means and embrace the looped wire portion thereof against one of the rods,

said clamping means including anvil surfaces to progressively receive the free ends of the legs of said wire loop during feeding movement and reversely bending said legs around the other of said rods in spaced parallel relation and directing the end portions of said legs in reversely directed straddling relation with respect to said first rod and in spaced relation to said first looped portion, and mechanism to twist said free end portions together around the first rod and thereby form a looped end embracing the first rod in parallel relation to said first looped portion.

3. The apparatus of claim 2, in which,

said clamping means includes a pair of parallel clamping members having outer hooked ends extending from a frame support to straddle said first rod and grip the other rod in said ends, said hooked end portions forming the extreme tip end of said apparatus.

4. The apparatus of claim 2, in which,

a single reciprocable actuator member is operatively connected to said clamping means, to said wire feeding means and to said twister mechanism, for clampingly engaging said pair of rods and feeding a wire loop into said reversely bent condition of the legs in response to a forward stroke of the actuator member, and, responsive to a return stroke thereof, withdrawing said fee ding means while twisting said free wire ends together and thereafter releasing said clamping means.

5. The apparatus of claim 2, in which,

a first pair of parallel clamping members having hooked end portions is provided at one end of a frame support for perpendicularly inserting said first rod between said members and extending to engage the other rod by said hooked end portions,

a clamping block mounted on the frame is provided with a second pair of parallel clamping members extending therefrom and movable to straddle said first rod in spaced relation to the first clamping members and to engage the tip ends of said hooked portions for releasably gripping said rods in clamped perpendicular relation, and

said twisting mechanism includes a rotatable wireend engaging means carried by said clamping block in endwise facing relation to and rearwardly adjacent said second pair of clamping members.

6. The apparatus of claim 5, in which,

said anvil surfaces are provided by curved grooves extending along the inside faces of said hooked end portions of the first pair of clamping members, and, in end-to-end registrable relationship therewith, grooves along the inside faces of said second pair of clamping members,

said rotatable wire end engaging means of the clamping block has an inwardly tapered conical recess with diametrically opposed grooves for receiving the free ends of said wire legs from the grooves of said second clamping means, and

a conical head member is positioned rearwardly in said recess for maintaining the wire ends seated in said grooves for a controlled twisting action thereof,

7. The apparatus of claim 6, in which,

said rotatable wire engaging means is a cylindrical member spring pressed forwardly in said clamping block and limited in endwise travel therein,

a spinner shaft, having a forward end slidably keyed in the rear end of said cylindrical member and its rear end held in a bearing at the opposite end of said frame support, is provided with an intermediate worm portion spaced rearwardly of said block, and

a spinner nut engages said shaft with a reciprocable actuator member, movable longitudinally on said frame support carrying said nut for travel along said worm section and imparting a rotary movement to said spinner shaft.

8. The apparatus of claim 7, in which,

said frame support comprises a pair of elongated laterally spaced parallel rail members,

said feeding means is a blade element slidably supported by and between the upper inner edges of said rail members on tracking grooves formed therein,

said clamping block is slidably supported on the fore section of the rail members for limited longitudinal movement and the fore-end of a clamp pusher member is fixed to the rear face of said block, said pusher member including side rails extending rearwardly along the outer side walls of said rail members with front and rear saddle portions connecting said pusher rails in bridging relationship over the top of said frame rail members,

said actuator member includes a pair of side rails slidably engaging the outer side walls of said pusher rails and a front saddle portion bridging said pusher side rails between said pusher saddle portions, and said spinner nut is fixed on said actuator saddle portion, and

said actuator saddle portion is drivingly connected with the end of said feeder blade element, said actuator side rails and pusher side rails are provided with a releasable clutch drive connection for forward movement of the clamp block, and said spinner nut, rearwardly of said shaft worm section, is engageable with said rear pusher saddle for retraction of said clamp block from its forward position. 

1. Apparatus for fastening and twisting a looped tie wire on crossed rod members comprising a frame having forked parallel end portions provided with arcuate wire forming surfaces and serving as a first anvil means, means for progressively feeding the legs of a U-shaped wire tie member in an endwise path of travel against said anvil surfaces to impart reverse bends in said legs lying in parallel planes normal to the plane of the looped end of said member, a second anvil means having forked parallel portions provided with surfaces for progressively receiving the bent leg portions from said first anvil means and rebending said portions to lie in spaced substantially parallel relation to the leg portions adjacent the looped end of said tie member, means associated with said second anvil means for receiving the tip ends of said legs therefrom and operable to twist said ends together, said first anvil means and the said second anvil means including said twisting means being relatively movable to close and separate said first and second anvil means to apply said Ushaped tie wire on a pair of right angular intersecting rods and upon separating movement to operate said twisting means.
 2. Wire-tie fastening apparatus for binding concrete reinforcing grids and the like at rod cross-over points, said apparatus having releAsable clamping means for holding a pair of rods together at right angles, means to progressively feed a pre-formed hair-pin like wire loop to said clamping means and embrace the looped wire portion thereof against one of the rods, said clamping means including anvil surfaces to progressively receive the free ends of the legs of said wire loop during feeding movement and reversely bending said legs around the other of said rods in spaced parallel relation and directing the end portions of said legs in reversely directed straddling relation with respect to said first rod and in spaced relation to said first looped portion, and mechanism to twist said free end portions together around the first rod and thereby form a looped end embracing the first rod in parallel relation to said first looped portion.
 3. The apparatus of claim 2, in which, said clamping means includes a pair of parallel clamping members having outer hooked ends extending from a frame support to straddle said first rod and grip the other rod in said ends, said hooked end portions forming the extreme tip end of said apparatus.
 4. The apparatus of claim 2, in which, a single reciprocable actuator member is operatively connected to said clamping means, to said wire feeding means and to said twister mechanism, for clampingly engaging said pair of rods and feeding a wire loop into said reversely bent condition of the legs in response to a forward stroke of the actuator member, and, responsive to a return stroke thereof, withdrawing said feeding means while twisting said free wire ends together and thereafter releasing said clamping means.
 5. The apparatus of claim 2, in which, a first pair of parallel clamping members having hooked end portions is provided at one end of a frame support for perpendicularly inserting said first rod between said members and extending to engage the other rod by said hooked end portions, a clamping block mounted on the frame is provided with a second pair of parallel clamping members extending therefrom and movable to straddle said first rod in spaced relation to the first clamping members and to engage the tip ends of said hooked portions for releasably gripping said rods in clamped perpendicular relation, and said twisting mechanism includes a rotatable wire-end engaging means carried by said clamping block in endwise facing relation to and rearwardly adjacent said second pair of clamping members.
 6. The apparatus of claim 5, in which, said anvil surfaces are provided by curved grooves extending along the inside faces of said hooked end portions of the first pair of clamping members, and, in end-to-end registrable relationship therewith, grooves along the inside faces of said second pair of clamping members, said rotatable wire end engaging means of the clamping block has an inwardly tapered conical recess with diametrically opposed grooves for receiving the free ends of said wire legs from the grooves of said second clamping means, and a conical head member is positioned rearwardly in said recess for maintaining the wire ends seated in said grooves for a controlled twisting action thereof,
 7. The apparatus of claim 6, in which, said rotatable wire engaging means is a cylindrical member spring pressed forwardly in said clamping block and limited in endwise travel therein, a spinner shaft, having a forward end slidably keyed in the rear end of said cylindrical member and its rear end held in a bearing at the opposite end of said frame support, is provided with an intermediate worm portion spaced rearwardly of said block, and a spinner nut engages said shaft with a reciprocable actuator member, movable longitudinally on said frame support carrying said nut for travel along said worm section and imparting a rotary movement to said spinner shaft.
 8. The apparatus of claim 7, in which, said frame support comprises a pair of elongated laterally spaced parallel rail members, said feeding means Is a blade element slidably supported by and between the upper inner edges of said rail members on tracking grooves formed therein, said clamping block is slidably supported on the fore section of the rail members for limited longitudinal movement and the fore-end of a clamp pusher member is fixed to the rear face of said block, said pusher member including side rails extending rearwardly along the outer side walls of said rail members with front and rear saddle portions connecting said pusher rails in bridging relationship over the top of said frame rail members, said actuator member includes a pair of side rails slidably engaging the outer side walls of said pusher rails and a front saddle portion bridging said pusher side rails between said pusher saddle portions, and said spinner nut is fixed on said actuator saddle portion, and said actuator saddle portion is drivingly connected with the end of said feeder blade element, said actuator side rails and pusher side rails are provided with a releasable clutch drive connection for forward movement of the clamp block, and said spinner nut, rearwardly of said shaft worm section, is engageable with said rear pusher saddle for retraction of said clamp block from its forward position. 